Get-ClusterRules

16/06/2017

I recently encountered an interesting question, maybe not the one you will see every day. A vCenter Center server runs a large number of Clusters; the VMs on those clusters are controlled by a considerable number of DRS rules. The question that raised; “How do we know if the DRS rules we once designed are still in place?” In the course of time, rules can be disabled, VM or Host groups does not match any more. Trying to answer this question by going through the vCenter Server configuration is not the way to go.

Thankfully, the VMware PowerCLI contains a useful Cmdlet Get-DrsRule that enables you to create a dump of the configured rules for each cluster. This makes checking your configuration a lot easier.

But there is another thing, now we know about the configuration, but what do we know about the actual situation? For instance, VM to Host affinity has “should” and “must” rules, but to what extent is a “should” rule fulfilled?

So time to create a PowerShell script which performs the following tasks; for each Cluster within a vCenter Server, a dump of the configured DRS rule is made. The second part of the script determines on which host a VM is running and compares it to the configured rules. The script will also report if a DRS rule is disabled and displays the power state of each VM. You will probably worry less about a powered down VM.

The script can be found here on GitHub.

I am aware that the script and my programming skills are far from perfect, so expect updated versions in the future.


vCSA how to disable IPv6?

18/04/2017

For me it was already a common practice to disable IPv6 on ESXi hosts, but until recently I did not realize that vCenter Server can also benefit from it. For vCenter Server on Windows, you reconfigure the Windows network configuration. But how do you disable IPv6 on the vCSA?

I recently found that a vCSA 6.0 has at least three options to reconfigure the network settings. But only one option enables you to disable IPv6.

Using a web browser you can log in to the vCSA Web console by entering URL: https: //<vCSA hostname or IP address>:5480

From there go to Networking, under Networking Interfaces, choose Edit to open the “Edit IP Configuration” window. Here you can configure IPv4 and IPv6 and disable IPv4, but no option to disable IPv6.

Fig.1

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The DevOps Handbook, a review

16/04/2017

You have probably heard or maybe have read the book “The Phoenix Project”, subtitle “A novel about IT, DevOps, and helping your business win”, written by Gene Kim, Kevin Behr and George Spafford. Written in a smooth style, in this novel, key figure Bill Palmer, Director of Midrange Technology Operations gets an unexpected promotion to Vice President of IT Operations. Minutes after his promotion he enters into a world of Chaos, mainly caused by the deployment of new software. This Phoenix project has been initiated to help Bill’s company “Parts Unlimited” to regain its market position. During this heroic journey, Bill is unexpectedly guided by a mysterious guy (Erik) who introduces him into the principles of the Three Ways, Continuous Delivery and much more. Eventually, the Development and IT Operations departments undergo a big transformation and the story ends well.

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vCSA default shell is BASH

14/04/2017

A quick post about a little caveat while working in the vCenter Server Appliance (vCSA) shells. Yes correctly, shells in plural. The vCSA is bundled with at least two different shells:

  • Appliance Shell (default)
  • BASH shell

The “Appliance shell” is the default shell. After you log in to the vCSA, it will present the following well known screen.
Fig 1.

The appliance shell can be used for updating the vCSA, using the software-packages command and has some other use cases. From here you can enable the BASH shell as shown in the Fig 1. for the duration of your session with the following commands:

# shell.set --en -s /bin/bash root
# chsh -s /bin/bash root

You can also set the BASH shell as the default shell by performing the following command. Make sure, you first enable the BASH shell as shown above:

# chsh -s /bin/bash root

For the change to take effect, log out and log in again. Now you will directly enter the BASH shell.

But while working in the BASH shell, you need to temporarily switch to the Appliance shell?
In that case, provide the following command:

# appliancesh

That’s it. A shell is nothing more or less than an executable; the “Appliance shell” is no exception and can be found as /bin/appliancesh.

For more information, see: VMware KB “Toggling the vCenter Server Appliance 6.x default shell (2100508)


Best way to create vCSA support bundles

09/04/2017

In general, during contact with a Customer Support team, whether being a Hardware vendor (Servers, Storage) or a Software vendor, the likelihood that you will be asked to upload some log files for further investigation is significantly.

In case of VMware vSphere, you will have multiple options for collecting a support bundle; to name a few:

  • Windows vSphere Client
  • vSphere Web Client
  • PowerShell scripts

See also VMware KB “Collecting diagnostic information for VMware vCenter Server 4.x, 5.x and 6.x (1011641)” for a complete overview.

Using some of these methods is very convenient; however there is a little caveat, when the vCenter Server is a vCenter Server Appliance (vCSA) 6.x.

Under certain conditions, a vCSA might contain core dump files. When requested to create a support bundle these core dump files will be added to the support bundle, together with the log files. The issue that may arise is that the location where the support bundle will be created (partition /storage/log) has a fixed size and possibly is too small.

Is that is the case, the creation of the support bundle will halt with error “Cannot create a diagnostic bundle” and the desired support bundle will not be created.

VMware recommendation is to create and download a support bundle using the web browser. To do so enter the following URL:
https ://<VCSA Hostname or IP address>/appliance/support-bundle

Fig 1

After providing the credentials, the support-bundle (filename is: vm-support.tgz) will start downloading. The progress of the process will be shown in the browser.

Using this method, the files will be directly downloaded to your local computer, instead of being prepared on the vCSA.

As always, I thank you for reading.


Do you need to know Network Virtualization ?

06/03/2017

Why NV?

20170304-01I recently took the VMware Certified Professional 6 Network Virtualization Exam. Preparation for a technical exam like one of the available VCP exams takes a lot of your free time, so why choose this one?
In recent years, I increasingly encountered the product NSX Manager, usually in VDI deployments with endpoint protection products like McAfee Move, Trend Micro Deep Security, to name a few. And while working on the upgrade of a VMware View environment, also comes the question, how to handle the endpoint protection part; How do we upgrade these components?
In the concept of the SDDC, besides the well known Compute and Memory providers, I consider Storage virtualization (like vSAN) and Network virtualization (NSX) as fundamental building blocks that should be part of your “basic” VMware knowledge.
I also noticed that VMware is doing a lot of promotion for the subject of micro-segmentation, and for a good reason.
So, I decided the time has come, to extend my knowledge. So where do you start? If you are on a VCP-DCV level, but cannot tell the difference between layer 2 and layer 3, I recommend start reading a book like “Networking for VMware Administrators” by Chris Wahl and Steve Pantol.
At that time, I was in between jobs with no budget, to attend regular VMware training courses like the “VMware NSX – Install, Configure and Manage” course.

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All Hands on Deck / VMware

19/02/2017

201701-01Although VMware is best known for its core virtualization product vSphere, it may not come as a surprise that since their first product releases, a lot has changed. Over the years, on top of this solid foundation, VMware built a “Software Defined Everything” stack (SDDC), a Cloud stack with all the Automation and Orchestration tools, Monitoring tools, an End User Compute environment etc. This has led to a very large number of VMware products.
As you are as curious as I am, product
data sheets and documentation maybe helpful, but the best way in my humble opinion is to download, install and try the bytes yourself.
In addition to options already there, VMware launched a new one; Product Walkthroughs. So time for an overview how to get familiar with these fine products.

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